A young shop assistant from a tiny rural New Zealand town has been identified as the mastermind behind a viral internet invitation that led to more than 3000 people gatecrashing a Dutch teenager's birthday and trashing the small Dutch town of Haren.

Six hundred riot police battled revellers who responded to an online hoax party invitation from Jesse Hobson, who lives in the Canterbury town of Dunsandel.

Haren, with a population of 18,000, was a riot scene at the weekend with cars set on fire, street signs smashed, and gatecrashers fighting elite police units. An 84-year-old resident was injured, as well as a number of police officers, and 34 arrests were made.

"Scum ran amok in our town," said Mayor Rob Bats.

And behind it all was a young New Zealander who thought it "would've been a bit of fun". Now, Mr Hobson, 21, accepts his party prank got out of hand. He claims to have received threats from a Dutch politician and even fears Dutch authorities will pursue him.

"I just thought it would've been fun. I didn't really intend it to go that badly," he told APNZ yesterday from the Dunsandel Store, where he works. "I was hoping for a good old-fashioned street party, with a few thousand people, good times."

Mr Hobson got involved in the "Project X Haren" party in an anonymous online forum.

The originator set up a Facebook page designed to crash a girl's "Sweet Sixteen" birthday party when she failed to set her Facebook event to private.

Mr Hobson then took over running the site, managing to escape being shut down by authorities and quickly getting the attention of 200,000 people. A total of 30,000 said they would turn up to the party, sending Merthe Weusthuis and her family into hiding and the town bracing itself for an onslaught of partygoers last Friday.

It took hundreds of police hours to calm the raging crowd.

Yesterday Mr Hobson said: "I didn't want it to turn into a riot, obviously ... But I might've been a bit optimistic, to be honest. I won't be going for a holiday any time soon, but the authorities might want me there."

Since the weekend debacle, which was headline news across the Netherlands and elsewhere in Europe, Mr Hobson has been identified by the Dutch press as the man behind the gatecrashing.

Although no official has contacted him, he is concerned that he could be extradited to Holland to face charges but is willing to face the music.

"I think part of the reason they wanted someone outside the country to administer the site was so it would add an international level that would complicate matters for anyone wanting to cancel the site."

He said he was "sorry it got out of hand" but blamed those who turned up wanting to cause trouble.

"There's not much I could've done about it. I was 18,000km away. They were the ones smashing windows, burning cars and motorbikes.

"But I probably won't be doing anything like it again."

Parties gone wrong

* Last month, pastor's son Richard Collis hosted a "Project X" party in Levin which was crashed by around 300 people. It ended with attacks on police, 19 arrests and allegations of animal abuse.* In 2008, Corey Delaney became the "poster boy for teenage stupidity" when his free-for-all party at his parents' Melbourne home was trashed by 500 drunk teenagers.* In 2007, a 17-year-old English girl was arrested on suspicion of criminal damage when 200 youngsters wrecked a family home after a party was advertised on MySpace.